Gilsonite conversion



Dec. 6, 1955 w. J. v BLOOMER GILSONITE CONVERSION Filed Dec. 30, 1952 w,R m m lJ 1 United States Patent Ofifice 2,726,196 Patented: Bees 6,1955 GILSONITE CONVERSION Ward J. Bloomer, Westfield, N. J., assignor toLummus Company,- New" York,-N-.-Y.,- a corporation of DelawareApplication Decemlier 30; 1952', Serial No; 322L738 Claims. (Cl. 196-50)This invention relates retire" recovery of available end p'r'oductsfromthe class of: material known as asphaltites of which gilsonite isap'articular example.

It" is known that'the asph'alt'ites and gilsonite in particular, is a'solid bitumen which has a melting 'point'irrthe orderot270" F. toabout400 F., normally contain's'less' than5 volatile matter and-has a fixedcarbon content in the range of 10'3()%'. The most particularcharacteristic of-gilsonite, however, is' the fact that when heated to'atemperature above 500 F., there is formed aconsiderable quantityof gas'andtherelease of substantial quantities of heat which tend to convertthe liquid gilsonite' directly into a solid' coke' material which has arelatively low value.

To -date, the difiicultiesin heating gilsonite to a necessary extenthavemade it impossible to recover the 'valu-' able hydrocarbons onacontinuous commercial basis; I

have' found that if the gilsonite is heated in the presence of a liquidhydrocarbon of selectedboilingzrange insuch' ratios that'the' exothermicheat can'belargely dissipated byi'the vaporization of the hydrocarbon,it is possible'to' heat the gilsonite to a suificientlyhigh degree sothat it can be-ultim'atelyreducedto a dry cokeby; chargingxitto of theliquid having suificiently high latent heat present so that enough ofthe exothermic heat is absorbed to pre vent excessive gassing andtemperature rise of the mixture. F or-this purpose, I prefer to use agas oil of about 700900 F. end point. Such a liquid has the advantagethat it'will tendto partially dissolve the gilsonite and being anadjacent fraction may be readily handled not only in a cracking heater,but in fractional distillation-equipment and in a continuous cokingoperation; There are other liquids however, which could be'used solelyfor the ab-' sorption of the exothermic heat which would'permit therecovery of the low boiling end products following the preliminarycracking stage. a

My invention further contemplates the reductionof the liquid residuefrom the first fractional distillation step to a dry coke which may beeffectively used as a circulating mediurnina continuous coking operationof the type described in the co-pending application of August'I-IenrySchutte Serial No. 252,306, filed October 20-, 1951.

The attached drawingshows a schematic view of the complete equipment forthe reduction of powdered gilsonite to its ultimate end products.

In accordance with a preferred form of embodiment of my invention,ground or pulverized gilsonite is collected ina hopper 1 from which itmay be distributed at a; desir ed" rate by the conveying mechanism Zintoa dissolving 2' tank 5. Tank -5 is'providedwith lock gates 3--and 4'tomaintain the tank in a closed manner.

The dissolving tank-5 is provided 'witha heating coil6 whichmay'beinterconnected 'to a: steam or other heat: source to maintain -the tankat about 500- F., the-'rnix ture being in a generallyliquid massresulting-from the addition of suitable diluent from the-line 7. Aheaters is provided in line 7 to bring the diluent'to the desiredsolutiontemperature. As heretofore described, this liquid-is preferably a highboiling hydrocarbon-ofithe general boilingrange of agas oil.Approximately /s :to /2 as much liquid is added to the tank aspowderedgilsonite. I

The gilsonite liquid mixture'is maintained as-aslurry or solution whichis preferably agitatedby the agitator 9 and is drawn oifwith-substantial uniformity through-the bottom drawoti 10 through thevalve 10a andis-pumped by the pump 11 to the heater 12 Heater i2 isasuitable coilheater which may be provided'with a convection as well asa main heat section. The oil is introduced at about 500 F. and" is thenheated to a temperature substantially above the tempera ture ofincipient coking an'd preferably'to about 776 775 F. during whichpartial cracking-takes place.

During the heating 7 period',- substantial quantities" of heat arereleased by the-"exothermic decomposition of the gilsonite? I have foundthat-if the diluent hasa sufficiently high latent heat and is'pre sentinsuficient' quantities}. enough of the exothermic heat is absorbed toprevent the gilsonite changinginto-coke. intact, the appearance-of theefrluentfrom the heater 12'at13 appearsto be=of"a heavy gas-oil nature.This material is introdueed-at the outlet temperature through valve 1&into the fractionating.

column 17: Introduction of the eilluent into the column may result insome foaming. Thisfcan-be eifectivelyflm hibited by the addition of asmall am'ount of an anti-foam agent, at the pointof introductiono'rat'somepo'inthigher up in the column. v

The column 17 is provided" with suitable 'fi actionating decks 18* andis preferably provided with l arelioiler'3 Column 17 may also be'providedwithsteam stripping ldfor the purpose of driving the light'ends oVerhead through the line 19;-

The overhead vapors comprising:cohdensi-ble andnon condensible portionsare withdrawn-- throughline 19: These may betreated in a conventionalmannerto-separate condensible hydrocarbon vapors from the'prod-uctsofgasification which include valuable amine compounds. The production andrecovery of the amine compounds from the raw gilsonite is one of theimportant features In a lower part of thetower"a-heavy-distillate-is-with drawn throughline 29 under the controlof'valv'30I Th" heavy distillate withdrawn is returned by lines 7z-and 7todissolvingtank-S. Some heavy distillate may appear in the asphaltbottoms in the lower part of the tower. While the presence of excessamounts of heavy distillate is not desirable in the asphalt bottomssince it will abstract heat from the coke-bed in the cokingi reactor,thepreseirce of some heavy distillate is desired to'maintai'n thecokercharge in partial dilution duringtransfer.-

It is generally desirable to reduce the gilsonite to its ultimate endproducts of gases, coker distillate and solid coke. This may beaccomplished by pumping the asphalt bottoms in line 34 to the continuouscoker indicated at 32 through which passes a continuous stream ofrelatively small, hard coke pebbles as disclosed in August H. SchuttesU. S. Patent 2,600,078.

The continuous coker 32 is maintained full of such carbon particles andthe liquid asphalt solution in line 34 is injected onto the coke pebblesat 36. This results in a continuous vaporization of the lighter ends ofthe charge by the preheated coke. The vapors are removed through thevapor outlet 35 and the coke particles continue to move downward throughthe outlet zone 42. A steam purging ring is provided at 43 below thevapor take-off 35 and in such position as to insure dryness of the cokeparticles as they pass downward and out through the outlet conduit 44.

Pressure is maintained in the reactor 32 sufficient to discharge thecoke particles through the line 44 to the vapor release chamber 45 fromwhich the particles flow through control valve 46 and through theseparator 47 with the desired size of particles passing into thereheater 51 through the inlet 52. Oversize particles may be removed fromthe bottom of the separator 47. Undersize particles may also be removedfrom the separator 47 and returned to the system through the line 48.

Reheater 51 is of a radiant type being provided with a series of burners53 in the upper part of the reheater, such burners being supplied by gasand air from the lines 54-55 in a well known manner. Particles of cokeare heated to the desired extent and continuously moved downward pastthe flue gas collector 57 with the flue gases removed at line 58 andpassed to the stack at 60.

Outlet from the reheater is through a series of lock and forwardingtanks 61 and 62 which are provided with suitable valves 63 and 64 thatare in turn operated in cycle manner by the controller 65. The tanks areprovided with steam inlets which are also controlled by the controllerto permit the movement of the coke particles to the reactor 32 by line37.

The vaporous material removed from the reactor 32 which is recoveredthrough line 40 is quenched by oil entering line 39, partially condensedand passed into the fractionator 41 from which a heavy gas oil isremoved at 72 and is used to supplement, if necessary, the hydrocarbonused as the gilsonite diluent. A lighter overhead material may beremoved at 71 and a heavier product may be removed at 73. The materialin line 73 may be recycled to the coker 32 if desired. 4

Example I In accordance with my invention a mixture of 75 weight percent of gilsonite, and weight per cent of a 100 neutral distillate blendwere heated in a lead bath type heater and introduced into anatmospheric flash chamber with the following results:

In an experiment carried out at 100 mm. Hg abs. in which a waxy gas oilblend was used as solvent and 100 parts per million of an effectiveanti-foam agent was added, the following results were obtained.

5 3 Heater Heater Overhead Run No res Bath Outlet Temp., Temp.,

Hg 5 F. F. Percent Example III In a further experiment carried out at100 mm. abs. in which a topped coker distillate recycled from batchcoking of gilsonite was used as solvent, with 100 parts per million ofan anti-foam agent added, the following results were obtained:

In all the foregoing runs, it will be noted that the heater temperaturewas maintained considerably above the normal coking temperature ofgilsonite with no coking of gilsonite occurring.

While I have found it desirable to direct the flow of heater effluentinto a flash or distillation tower as previously described, I alsocontemplate charging the heater eflluent directly to the coking reactorby line 13a, by-passing tower 17. The presence of considerablequantities of diluent along with other gasiflcation products willabstract some heat from the coking reactor bed and the end productdistribution obtained in the coking reactor will vary somewhat from thatobtained in the heater-tower system because of temperature andprocessing diiferences. The desired arnine compounds can be recoveredalong with the diluent in the coking distillate tower 41. Condensedreaction product with desired diluent properties may be returned to thedissolving tank along with the original diluent.

It is apparent that my invention provides a simple method of treatinggilsonite to obtain valuable products therefrom by effectively avoidingexothermic heat and the accompanying formation of coke.

It will be evident to those skilled in the art that variousmodifications of this invention can be made in view of the foregoingdescription without departing from the spirit or scope of the disclosureor from the scope of the appended claims.

I claim:

1. The method of recovering valuable hydrocarbon constituents of anormally solid asphaltite, which comprises forming a solution of groundasphaltite together with a high boiling hydrocarbon liquid having an endpoint of between 700 to 900 F. and directly heating such mixture to acracking temperature above the incipient coking temperature of theasphaltite in the absence of coke formation, the quantity of liquid andits latent heat being such that the exothermic heat given ofi by theasphaltite during heating and cracking is largely dissipated in thevaporization of the high boiling liquid.

2. The method of recovering valuable hydrocarbon constituents of anormally solid asphaltite which comprises forming a solution of groundasphaltite with a high boiling liquid hydrocarbon, heating the mixturedirectly to a cracking temperature above normal coking temperature ofthe asphaltite in the absence of coking, the quantity of liquid and itslatent heat being such that exothermic heat given off by the asphaltiteis dissipated in the vaporization of the high boiling hydrocarbon andcoking of the asphalitc during heating is prevented, and introducing theefiluent from the heating step into a fractionator to recover valuableoverhead and bottoms products.

3. The method of recovering valuable constituents of a normally solidasphaltite as claimed in claim 2 in which the bottoms from thefractionator are converted to dry coke and vaporous overhead and saidoverhead is condensed and used in part as the liquid solvent for theasphaltite.

4. The method of recovering valuable constituents of a normally solidasphaltite which comprises forming a solution of ground asphaltite witha high boiling liquid hydrocarbon diluent, heating the mixture directlyto a temperature above which the asphaltite normally cokes and at whichsome cracking of the asphaltite occurs, absorbing exothermic heat fromthe asphaltite during cracking by direct vaporization of the highboiling liquid hydrocarbonate diluent and preventing the formation ofcoke during said heating, introducing the vaporized hydrocarbon diluentand cracking products of the asphaltite into a distillation tower,recovering an overhead product including amines and condensiblehydrocarbons, withdrawing a side cut of a high boiling hydrocarbon fromsaid tower suitable as the asphaltite diluent, withdrawing asphaltbottoms from said tower and converting said bottoms to a valuable cokeproduct.

5. The method of recovering valuable constituents of a normally solidasphaltite as claimed in claim 4 wherein the withdrawn asphalt bottomsare in the presence of at least a portion of the hydrocarbon diluent.

6. The method of recovering valuable constituents of a normally solidasphaltite as claimed in claim 4 wherein at least a portion of thecondensible hydrocarbons are condensed and returned to the tower as areflux.

7. The method of recovering valuable hydrocarbon constituents and aminesfrom normally solid asphaltites which comprises mixing ground asphaltitewith a high boiling liquid diluent, heating the mixture to a temperatureabove the incipient coking temperature of the asphaltite at whichcracking of the asphaltite will occur, removing exothermic heat releasedby the asphaltite during heating by direct vaporization of the highboiling liquid diluent so that no coking of the asphaltite occurs duringcracking, passing heated effluent to a vacuum distillation tower,removing tower overhead comprising amines and hydrocarbon vapors,separating the amines and condensed hydrocarbon vapors and returning atleast a portion of the condensed hydrocarbons as tower reflux,withdrawing an intermediate cut from said tower having a high boilingpoint and suitable as asphaltite solvent, returning said side out to bemixed with ground.

8. The method of recovering valuable hydrocarbon constituents fromnormally solid gilsonite which comprises mixing ground gilsonite with ahigh boiling liquid hydrocarbon diluent, heating the mixture to atemperature above the incipient coking temperature of the gilsonite inthe absence of coke formation with partial cracking of the gilsonite,removing exothermic heat released by the asphalt during heating bydirect vaporization of the high boiling liquid hydrocarbon diluent,passing the vaporous products of heating which include the vaporizeddiluent to a coking reactor, coking the efiiuent therein, passing vaporsfrom the coking reaction to a coking distillate recovery tower,withdrawing an overhead product from said recovery tower comprisingamines and condensible hydrocarbons, withdrawing a side out suitable asa gilsonite solvent and withdrawing an asphalt bottoms as product.

9. The method of recovering valuable hydrocarbon constituents ofnormally solid gilsonite as claimed in claim 8 wherein the amines andhydrocarbons present in the overhead from the distillate recovery towerare separated and at least a portion of the condensed hydrocarbons isreturned to the distillate recovery tower.

10. The method of recovering valuable hydrocarbon constituents ofnormally solid gilsonite as claimed in claim 8 wherein the withdrawnside out is returned as ground gilsonite diluent and the asphalt bottomsfrom the distillate recovery tower are returned to the coking reactor.

References Cited in the file of this patent UNITED STATES PATENTS1,940,725 Morrell Dec. 26, 1933 2,006,186 Stines June 25, 1935 2,067,810Angell Jan. 12, 1937 2,105,874 Aldridge et a1. Jan. 18, 1938

1. THE METHOD RECOVERING VALUABLE HYDROCARBON CONSTITUENTS OF A NORMALLY SOLID ASPHALTITE, WHICH COMPRISES FORMING A SOLUTION OF GROUND ASPHALTITE TOGETHER WITH A HIGH BOILING HYDROCARBON LIQUID HAVING AN END POINT OF BETWEEN 700 TO 900* F. AND DIRECTLY HEATING SUCH MIXTURE TO A CRACKING TEMPERATURE ABOVE THE INCIPIENT COKING TEMPERATURE OF THE ASPHALTITE IN THE ABSENCE OF COKE FORMATION, THE QUANTITY OF LIQUID AND ITS LATENT HEAT BEING SUCH THAT THE EXOTHERMIC HEAT GIVEN OFF BY THE ASPHALTITE DURING HEATING AND CRACKING IS LARGELY DISSIPATED IN THE VAPORIZATION OF THE HIGH BOILING LIQUID. 